Just a few days after comedian Tig Notaro was diagnosed with breast cancer, she found herself on stage at Los Angeles' Largo theater, revealing the news of her illness and delving into other personal struggles. The performance, which is now officially known as "Tig Notaro Live," was destined to make waves across the Internet and inspire all who listened to it.

"It was right in the moment of - everything in my life was falling apart," Tig says of that night. "And when I went on stage, I was in the middle of that crisis and it was captured on audio."

She tries to pinpoint why people responded so strongly to the set, saying, "People that have had cancer or any sort of turmoil in their life that they can kind of relate to - I think that's what is touching people so much."

The introspective performance was a surprise for everyone, including Tig herself, who never really expected to speak about such profound issues during a scheduled stand-up routine. "I didn't really go that deep with my comedy," she says, adding that she generally picks observational topics and responds to silly humor.

As a special guest in the audience that night, fellow comedian Louis C.K. offered to post the audio on his site, believing that people should be able to hear Tig's powerful words. While Tig was initially hesitant to further publicize what she calls a 30-minute, off-the-cuff open mic, less than two months later, she gave him permission to post it, and then it just went viral across the Internet.

"I thought that I would have a lot of backlash because people would read it and think, 'This isn't hilarious,'" Tig says. "There are funny parts to it, but it's more a moment in time." But all of the feedback that she saw was truly positive.

It was very helpful for her healing process as well. "I was so keenly aware that not everybody gets to be lifted up by the world when you're in utter turmoil," she reveals.

"I don't know the numbers at this point, but, last I knew, it had sold in 5 weeks well over 100,000 copies," she says, adding that a percentage of the profits are being donated to cancer research and various charities.

While the live audio recording is no longer available on Louis C.K.'s site, you can buy it on iTunes.